Transmission Position Sensor/Switch: Description and Operation
The Inhibitor Switch, located on the right side of the transmission, signals the ECU as to transmission operating range and prevents starting the vehicle except in "P" or "N" positions. The signal is sent to the EC-AT control unit which then relays it to the ECU.
The ECU utilizes gear position input from the inhibitor switch in its calculations for these outputs:
Fuel injection quantity
Idle speed control
Purge control
Igniter (timing control)